I agree with Erin. Some people go so far as to tape a picture of their friend on the camera. If you have a topic you love - start with that. Your passion will come through.
Content is most important, then audio, then lighting. A mic is great to use, but if you don't have one just go to a quiet spot.
The first vlog is often the biggest hurdle for people to get over. I always tell my followers at http://simplevloggingtips.com to start with what they have - even if it's only a webcam. Make a short video - no more than a minute and post it where friends will watch and give you good feedback. Then as you do more you'll know what equipment you will want to buy.
I could talk all day on this subject so I'm just going to end with
Happy Vlogging!